Metallic baffle construction



06b9, 1934. s MENQUGH 1,976,262

METALLI C BAFFLE CONSTRUCTION Filed Jan. 19, 1932 2 Sheets-Sheet l .11 7 g B401 5. MEA/OUGH duom s Oct. 9, 1934. P. sv MENOUGH I 1,976,262

' METALLIC BAFFLE CONSTRUCTION Filed Jan. 19, 1932 v- 2 Sheets-Sheet 2 gwuentoo- 5/ ll 7 4 B401 5. MEN-0066 Patented Oct. 9, 1934 esrsnr orr cs METALLIC BAFFLE CONSTRUCTION Paul S. Menough, Mount Lebanon, Pa., assignor to The Duraloy Company, Pittsburgh, Pa., a corporation of Delaware Application January 19,

Claims.

The present invention relates to bafiie plates and more particularly to those for use in connection with boilers, stills and the like.

In the construction of modern boilers and stills 5 wherein banks of tubes are employed considerable effort and means have been expended and employed to confine and prolong the flames and burning gases through a directed path over and along the boiler tubes through the provision of N suitable bafile walls. Bafiies have inmost instances heretofore been assembled and constructed of a refractory material such as tile, firebrick, terra cotta and the like, the same being more or less permanently built into the boiler construction and supported either by the tubes themselves or by the walls or base of the boiler assemblage.

In other instances metal bafile plates have been employed in an endeavor to eliminate the many unsatisfactory results derived by the use of refractory material in that the cost of initial installations and subsequent replacements are far above that for metal baffles. Also the time and labor expended in the installing and repairing of the same is prohibitive in view of the use of metal In the use of a baffle made of a refractory material or the like as hereinabove referred to the changes of temperature due to varying fire conditions, the alternate and uneven expansion and contraction of the relatively non-resilient refraction unit resulting in disintegration, loosening and cracking of the unit permitting particles to drop out of place, thereby producing holes in the bafiies which act to by-pass the intended flow of heat,

creating dangerous hot spots, while other tubes in the intended path of flow are deprived of the heat thus diverted, caused a condition which was wholly unsatisfactory. It is obvious, therefore,

' that a baffle constructed of a refractory material has many undesirable features in that the particles which drop out of place not only weaken and deteriorate the baffle, but lodge between other tubes and deflect, and in some instances, wholly bar the path of the intended flow of heating gases. The dislodged particles also work into the mechanical mechanism of the furnace and result in serious injury thereto.

To overcome the above enumerated disadvantages of the use of refractory material in baffle construction, various attempts have been made to provide a metallic bafiie, among which is of the general type disclosed in the patent to Mills, No. 1,715,614, issued'Januaryl i, 1929 entitledjBafiies 1932, Serial No. 587,552

for boilers, stills and the like, which have been successful except that considerable difiiculties have been encountered due to the thickness of the plate necessary to withstand the severe conditions attending apparatus of this nature and adding destructive and deleterious weight to the tubes. Another difiiculty which has been encountered is the inadequate means to retain the relatively heavy plates in position and at the same time providing suitable means to allow for the expansion and contraction of the plates. The multitudinous points at which it was necessary to support flat plates from the tubes and the type of joint therebetween provided soot collecting points which are undesirable, the soot having a heat insulating effect on the tubes which it surrounds.

It is, therefore, among the objects of my invention to provide a metallic baffle which will be of minimum weight having maximum strength P and durability and requiring the minimum number of supporting points for a given area ofbaffle. It is a further object of this invention to provide a baffle which will not warp under any local stresses which might be set up by localized heating, which will be flexible under repeated heating and cooling, which will be readily interchangeable, movable and uniform for various types of installations. It is a still further object of this invention to provide a corrugated metal baffle in- P eluding a novel clamping means for loosely securing the lapped edges of the independent baffle members together as well as to the banks of tubes. I

Other objects and advantageous features of my invention will be more apparent from the following detailed description taken in conjunction with the drawings wherein similar characters of reference designate similar parts and wherein:

Figure 1 is an elevational view of a boiler illustrating an application of the preferred embodiment of my invention.

Figure 2 is an enlarged sectional view taken on the line 2--2 of Figure 1.

Figure 3 is an elevational View of a boiler construction embodying a modified form of my invention.

Figure 1 illustrates a further modification of my invention.

Referring to the drawings and particularly Figure 1 there is illustrated one type of boiler construction employing a plurality of banks of tubes 5 which are adapted to connect the mud drum '7 to the headers 9 and 11. The baffle plates of suitable alloys which are capable of withstand ing the high temperatures attendant in steam boiler practice. Elongated holes 14 extending laterally of the corrugations are provided adjacent the edges of the plate to receive a clamping member or hangers 15 for retaining the corrugated sheets in position on the tubes. The clamping hangers 15 are provided as required laterally along the tubes at the overlapping edges of the sheets or plates 13. The hangers 15 comprise U-shaped bolts 17 adapted to partially encircle the tube 5 and parallel legs which extend beyond the tube and pass through apertures 21 in a clamping member 23. The clamping member 23 is formed with an arcuate recess as at 25 adapted to engage the tube 5 and thus retained in fixed position by suitable nuts 27. A raised planular surface 26 is provided opposite the armate recess to form a bearing surface adapted to be engaged by the overlapping ends of the corrugated plates 13. The legs of the bolts 17 extend beyond the members 23 and 2'7 and are received in apertures 29 in a plate retaining member 31. This member is provided with a raised arcuate boss 33 midway between the apertures 29 adjacent the tubes. The arcuate surface of this member is adapted to seat loosely in the concave portion in one of the corrugations of the plate 13. The contact retaining and adjusting nuts 35 are threaded on the end of the legs 19 exterior of the member 31.

It will be seen that the overlapping plates 13 are held in position between the surfaces 26 and 33 of the clamping members 21 and 31 although the engagement between adjacent plates is loose enough to permit a limited relative expansion thereof. It is also apparent that the plates may be readily adjusted or replaced without removal or disturbance of the hanger unit.

Referring now to Figure 3 there is illustrated a modified form of my invention used in conjunction with boiler construction comprising a plurality of banks of tubes 40 and 41 connecting a mud drum 42 with a header 43. Attached to the rear-most tube of the bank of tubes 40 and spaced from the header 43 by means of a plurality of saddle blocks 44 is one end of a series of relatively thin corrugated plates 45. The plates are secured toegther as at 46 and extend downwardly permitting free contraction and expansion of the battle independently of any securing means. This modification further provides a minimum of points of securement and contact of the bafile to the tubes and the attendant soot collecting points. Similarly a bafile 4'7 comprising a plurality of relatively thin corrugated plates 48 secured. together, having one end thereof secured to the outside tube of the bank of tubes 41 closely adjacent the header 43 as at 49 is provided.

In Figure 4 there is illustrated a baffie comprising two corrugated plates placed back to back and having the corrugations of the respective plates normal to each other. Such a battle is used where additional strength is needed. The

plates 50 and 51 are spot welded together at spaced points and baflles so formed can be used and secured to the banks of tubes in a similar way as shown in Figures 1 to 3 inclusive.

It is among the advantageous features of this invention that it contemplates the provision of a thin gauge corrugated alloy bafiie sheet which will minimize the initial cost of the bafiie, is interchangeable and readily movable, sumciently compact for installations in closely banked tubes; presents strength and stiffness through its corrugations which minimizes the number of supports and allows maximum flexibility by expansion and contraction under diverse heating and cooling conditions within the boiler; allows readily overlapping of the ends and edges which form a sufficient sealing between the plates and which is non-warping under local heat stresses.

Although the foregoing description is necessarily of a detailed character in order to completely set forth this invention it is to be understood that the specific terminology is not intended to be restrictive or confining, and it is further understood that various re-arrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. A baffle disposed between spaced banks of tubes in tubular boilers comprising a plurality of relatively thin corrugated plates disposed longitudinally of said tubes and having their lateral edges in overlapping relation.

2. A baffle disposed between spaced banks of tubes in tubular boilers comprising a plurality of relatively thin corrugated plates disposed longitudinally of said tubes and having their lateral edges in overlapping relation, and means for attaching the plates to the tubes.

3. A baffle adapted to be disposed intermediate of spaced banks of tubes in a boiler, said bafile including a plurality of corrugated plates, and means for attaching said plates to said tubes.

4. A bafile adapted to be disposed intermediate of spaced banks of tubes in a boiler, said bafile including a plurality of corrugated plates, and means for clamping the overlapping edges together and to the tubes.

5. In a boiler having spaced banks of tubes, a

bafile for directing heat and burning gases overs the tubes comprising a plurality of relatively thin plates positioned between said tubes, said plates being corrugated and having their lateral edges disposed in overlapping relation to permit limited free relative expansive and contractive n1ove-" ment.

6. In a boiler having spaced banks of tubes, a baffle for directing heat and burning gases over the tubes comprising a plurality of relatively thin corrugated plates having their lateral edges dis-i posed in overlapping relation to permit limited unrestricted and independent expansion and contraction, means for attaching said plates to the tubes at their overlapping edges, said means permitting movement of the plates relative thereto.

'7. In a boiler having spaced banks of tubes, a battle for directing heat and burning gases over the tubes comprising a plurality of corrugated plates having their lateral edges disposed in overlapping relation to permit limited unrestricted:

and independent expansion and contraction, and means for supporting said plates in relatively movable, spaced and substantially parallel relation with respect to said tubes.

8. In a boiler having spaced banks of tubes,

10. A bafiie adapted to be disposed intermediate of spaced banks of tubes in a boiler, said bafiie comprising a plurality of corrugated heat-resisting alloy sheet metal plates, saddle blocks and clamp bolts for securing said plates in edge-overlapping relation to permit relative movement therebetween and for supporting the plates in operative position with respect to the tubes, said plates being formed with elongated slots to accommodate said bolts and permit relative movement between the plates and bolts.

PAUL S. MENOUGH. 

